Placeholder17
Well-known member
I have finished complete disassembly/cleaning/relubrication of a Porter-Cable 503 worm gear belt sander I picked up before the holidays. This model has an oil hole and a sight glass.
I was not the first person to take this apart, some previous owner had decided to replace a couple of flat-edge screws with hex cap screws of a large diameter and stripped a few holes in the process. Also, for some mysterious reason the front bearing had been replaced with a double open-ended bearing that was of course completely dry with its grease flung out around the bore in the housing. The brass helical gear was of course destroyed and the entire gearbox was smeared in brass oily paste. The shoe was missing as well.
I sucked it up and bought a new gear off of Ebay (they cost almost as much as buying the sander itself), new bearing, and shoe. Of the two rotor seals, the one at the fan was the original leather and undamaged but the seal at the rotor end was the more modern rubber ring and was partially torn. I glued the tear back together with JB Weld Clearweld and gingerly filed off the buildup within the bore of the rubber ring with a round file. In a first time experience for me, while scrubbing the needle bearings in the wheels with a cutip and acetone, the rollers started falling out..... It turned out they were just loosely aligned in the thin steel guides, so they were also easy to put back together. I'm not sure if that is original or due to wear; I found basically no grease or oil in them during cleaning.
I finished reassembly today and have greased the chain and wheels, but I want to confirm the oil level for the gearbox. I bought ISO VG 460 (Mobil SHC 634) oil instead of SAE 90 weight in the hopes of better preserving the brass gear.
I was not the first person to take this apart, some previous owner had decided to replace a couple of flat-edge screws with hex cap screws of a large diameter and stripped a few holes in the process. Also, for some mysterious reason the front bearing had been replaced with a double open-ended bearing that was of course completely dry with its grease flung out around the bore in the housing. The brass helical gear was of course destroyed and the entire gearbox was smeared in brass oily paste. The shoe was missing as well.
I sucked it up and bought a new gear off of Ebay (they cost almost as much as buying the sander itself), new bearing, and shoe. Of the two rotor seals, the one at the fan was the original leather and undamaged but the seal at the rotor end was the more modern rubber ring and was partially torn. I glued the tear back together with JB Weld Clearweld and gingerly filed off the buildup within the bore of the rubber ring with a round file. In a first time experience for me, while scrubbing the needle bearings in the wheels with a cutip and acetone, the rollers started falling out..... It turned out they were just loosely aligned in the thin steel guides, so they were also easy to put back together. I'm not sure if that is original or due to wear; I found basically no grease or oil in them during cleaning.
I finished reassembly today and have greased the chain and wheels, but I want to confirm the oil level for the gearbox. I bought ISO VG 460 (Mobil SHC 634) oil instead of SAE 90 weight in the hopes of better preserving the brass gear.
- Is the proper fill level just enough to fill the entirety of the glass, or to the bottom of the oil hole bore?
- I take pictures along the way for disassembly of all of my tools. If anyone in the future needs pictures of installation sequence of a few parts, just post here. There is definitely a very particular order for all the pieces along the rotor shaft between the rotor and the impeller.
